Project Summary/Abstract Preterm birth occurs at < 37 weeks gestation. It is associated with a host of newborn risks that increase the risk of preterm related infant death. The United States leads other industrialized nations in preterm birth rate and, for reasons unknown, non-Hispanic Black women in the U.S. have a 50% higher preterm birth rate compared to the overall national prevalence. Current preterm prevention strategies are limited due to lack of understanding about the underlying mechanisms of preterm birth. The association between intrauterine infection and preterm birth is well-established. Emerging research suggests that periodontal disease may be an etiologic source of this infection. Periodontal disease is an inflammatory condition that begins as a direct immune response to microorganisms that inhabit the subgingival biofilm. Pregnant women and racial/ethnic minorities are particularly at risk for periodontal disease. Gingival inflammation during pregnancy may allow for the movement of inflammatory products into the circulatory system and to the maternal-fetal unit, triggering an inflammatory cascade which may increase the likelihood of preterm birth. Critical to understanding the association between periodontal disease and preterm birth, is an understanding of the subgingival microbiome. This study, therefore, aims to: 1) Characterize the structure and diversity of the subgingival microbiome and of pregnant non-Hispanic Black women in early and late pregnancy. 2) Explore the relationship between the subgingival microbiome and localized inflammation. 3) Explore associations between localized and systemic inflammation, and gestational age at birth. Results from this study will inform an innovative approach to the assessment and intervention of periodontal disease in pregnant women as a potential modifiable target risk factor for preterm birth, thereby promoting maternal health, and preventing adverse birth outcomes for women and their newborns. The overarching goal of this K01 career development proposal is the development of Dr. Yang?s expertise in three areas: microbiome data analysis, oral health research, and health disparities research. The proposed project, in conjunction with the structured mentoring and training plan which includes didactic courses, workshops, and hands-on experience, are designed to facilitate this goal, as well as Dr. Yang?s long-term goal of developing an independently-funded biobehavioral research program that investigates how physiologic mechanisms combine with social, behavioral and environmental factors to give rise to maternal health disparities.